The current use of LED (light-emitting diode) as a backlight of electronic devices more and more. Current electronic devices such as televisions, computer displays, etc. can often work in 2D mode or 3D mode. At present, in the three-dimensional mode, the current flowing through the LED needs to be higher than the two-dimensional mode to provide sufficient backlight brightness in three-dimensional mode. Therefore, when the electronic device is operated in three-dimensional mode, it is necessary to increase the current of the LED, and when the electronic device is operated in the two-dimensional mode, it is necessary to reduce the current of the LED. However, the existing implementation in the three-dimensional mode to improve the LED current circuit structure is more complex.